diff --git a/metznet/services/sssd.scm b/metznet/services/sssd.scm
index 596da1c..7098a09 100644
--- a/metznet/services/sssd.scm
+++ b/metznet/services/sssd.scm
@@ -70,8 +70,7 @@
 
 (define-configuration sssd-configuration
   (sssd (file-like sssd) "sssd package to use")
-  (pam-services (list-of-strings (list "su" "sddm" "login" "sshd"
-                                       "passwd"))
+  (pam-services (list-of-strings (list "su" "sddm" "login" "sshd" "passwd"))
                 "list of pam services to configure login for"
                 (lambda (a b)
                   ""))
@@ -139,8 +138,11 @@
             (user (getpw "root")))
         (mkdir-p/perms dbusdir user 493)
         (mkdir-p/perms dbdir user 493)
-        (copy-file #$(sssd-configuration-file config) "/var/lib/sss/sssd.conf")
-        (chmod "/var/lib/sss/sssd.conf" #o600))))
+        (unless (file-exists? "/var/lib/sss/sssd.conf")
+          (begin
+            (copy-file #$(sssd-configuration-file config)
+                       "/var/lib/sss/sssd.conf")
+            (chmod "/var/lib/sss/sssd.conf" #o600))))))
 
 (define-public sssd-service-type
   (service-type (name 'sssd)